PRP for Hock Degenerative Joint Disease

Hock degenerative joint disease, also known as bone spavins, is quite serious and can cause lameness and loss of full function of the horse’s hocks. This disease occurs when the cartilage which protects the bones of the joints, becomes destroyed overtime. Degenerative joint disease affects the hocks (ankles), though it also occurs in other joints.

Hock degenerative joint disease can be caused for a number of reasons, for instance, as a result of loose joints or trauma. Some horses are more susceptible to hock degenerative joint disease then others because of inherited factors. Abnormal growth patterns may cause the development of the disease as well. As time passes, the cartilage begins to erode and overtime, the bones in the ankle may begin to grind against each other. Sports horses that suffer from hock degenerative joint disease may also experience lameness.

Hock degenerative joint disease can develop after some sort of trauma has occurred to the hock. The older the horse is, the more susceptible it is to developing the disease. However, it can also develop as a result of hereditary. In these instances, a horse will naturally have a higher risk of developing it than others. However, hereditary tends to play a bigger role in conditions such as navicular syndrome, hip dysplasia and OCD. When a horse is injured, degenerative disease may begin to present itself.

Breeds of horses which tend to naturally grow larger and heavier have an increased risk of developing hock degenerative joint disease because bigger bodies cause a greater amount of stress to be placed on weight-bearing joints.  However, overuse can increase the likelihood that this type of condition develops as well as can improper shoeing.

Hock degeneration joint disease can be very painful.  It may result in a horse’s inability to function and move normally. Sports horses will be especially affected. A horse may no longer be able to perform once the disease has degenerated to and past a certain point.  In addition to pain, a horse’s hocks or ankles may begin to swell and become stiff. A horse’s ability to move about and engage in certain activities will slowly begin to diminish.

Hock degeneration joint disease can be treated a number of different ways. Analgesic, anti-inflammatory medications (e.g., Acetaminophen, NSAIDs), cortisone and visco-supplementation, are amongst the most common ways it is treated. PRP (Platelet Rich Plasma) therapy is a treatment that is growing in popularity for this and other conditions which effect horses.  Platelet Rich Therapy utilizes a horse’s own platelets to promote the healing of soft tissue and bone injuries. It can help increase the rate in which an injury heals. It is currently used to treat human beings and has proven to be very successful in this regard. It is in part, due to this success, that it is being used with increased regularity to treat horses that suffer from soft tissue and bone injuries. We will talk more about PRP therapy, later in this article.


A horse may develop hock degeneration joint disease as a result of heredity, weight, trauma, loose joints and age. We’ll discuss these aforementioned causes in a bit more detail below.

a. Heredity: Breeds of horses that are naturally larger or those that become extremely large due to a poor diet and/or lack of exercise, are more prone to degenerative joint disease, including those of the hock joints. Obviously, not much can be done for horses that are naturally heavier and bigger. In these cases, care should be taken to prevent the development of the disease as much as possible and proper care should be given once a problem of this nature is detected.

b. Weight: Keeping a horse at a healthy weight is one way to help prevent the onset hock degeneration joint disease.

c. Trauma: Trauma is one of the most common reasons horses develop hock degeneration joint disease. In fact, this is often how it starts out. An injury of the hocks or ankles causes the joints of the bones to slowly degenerate and waste away.

Initially, a horse may appear to feel stiff after exercise. Slowly and overtime, the condition will worsen until it becomes impossible for performance horses to perform at a level they once did or be as active as they once were. It will also affect the ability of horses owned for casual riding, to function fully. This is especially true if adequate treatment and care isn’t provided.

d. Loose joints: Loose joints can also lead to hock degeneration joint disease. When a horse’s body isn’t structurally sound, all types of problems can begin to develop, including those of the degenerative variety. Loose joints make a horse more prone to injury, especially an active or performance horse.

Injury to the hock(s) or surrounding area(s) can become a precursor to hock degenerative joint disease. Thus a horse that has loose joints could more easily hurt itself and then begin to develop the aforementioned. Special precautions will need to be taken to lessen the likelihood that the horse gets injured. Unfortunately, and obviously, it’s not possible to totally prevent these types of conditions.

e. Age: Just like human beings, the older a horse gets, the more prone it is too developing degenerative diseases. With age comes overuse and age-related issues. Because bodies lose strength and at times, coordination, injuries are easier to come by.

An older horse may be more likely to hurt itself then it may have been when it was younger. Also, activity which may not have had a negative physical effect on a horse when it was younger may suddenly begin to and increased incidence of injury may be the result. For instance, a great deal of running and jumping cause injury when it wouldn’t have in the past. Again, there is a connection between injury/trauma and hock degenerative joint disease.

As a horse age, the hocks and joints will naturally begin to wear down, making them more prone to injury and thus degenerative diseases. Not surprisingly, older horses are most likely to develop hock degenerative joint disease.


When a horse develops hock degeneration joint disease, it will exhibit certain symptoms. They include but are not necessarily limited to, inflammation and stiffness for a period of a few weeks. Initially, after the horse has exercised, the hock joints may ache. Crepitus and the inability for a horse to perform at a level that he once did, without any problems are additional symptoms.

Inflammation: A horse that is suffering from hock degeneration joint disease will experience some inflammation in that area. This can be determined by palpitating the area.  Swelling may also be visually apparent.

Stiffness: Stiffness may develop after a horse has been still for a fairly long length of time, for instance after sleeping or standing for a period of time. If upon awakening or after standing still, a horse appears to have a difficult time getting going again, this may be because of hock degeneration joint disease. This could be for other reasons as well. Further testing will be required.

Aches: A horse suffering from this condition will experience some achiness. This will typically be most notable after activity, for instance, after exercise, performance, running or trotting. This achiness will make it difficult for the horse to participate in intense activity. This is especially true the further the condition progresses.

Loss of Performance Ability: A horse with hock degeneration joint disease won’t be able to perform at the level it once was able to. This will quickly become apparent amongst sports and performance horses. In fact, it may spell the end of their career.

Crepitus of the Joints: Crepitus may be a symptom that the joints are experiencing wear. Crepitus in the joints is characterized by cracking, grinding sound under the skin. A horse may also experience a grating sensation. It is important to note that though crepitus can be a bit nosy, it may or may not be painful for the horse.

Bumpy Appearance: The appearance of the hocks may appear bumpy and swollen. This bumpy appearance based will likely signal the presence of hock degeneration joint disease to the trained eye. A veterinarian is likely to recognize it almost immediately, though further diagnostic testing will be necessary to be sure.

In summary, the aforementioned symptoms are common for horses suffering from hock degeneration joint disease.  These symptoms will be considered by veterinarians, after which radiography will be used to make a definitive diagnosis.


A veterinarian has numerous tools at its disposal to make a diagnosis of hock degeneration joint disease. To begin, an orthopedic examination will be performed. This examination will test for tenderness, inflammation and pain in the joints. Radiography is also used. It is very useful for the purpose of a hock degenerative joint disease diagnosis. This is an important diagnostic tool because often times, when younger horses develop the condition, it is as a result of either a congenital defect or trauma.

Additional testing may also be needed. If it is, a vet may order a contrast dye radiograph test where contrast dye is injected into the joints. This will allow the vet to get a closer look at the joints. It also allows the doctor to obtain “stress” views. Bone scans may also be used. Force plate analysis is sometimes also utilized to determine what degree of lameness the horse is suffering from.


Hock degeneration joint disease can be treated a number of different ways. After a veterinarian has made a diagnosis, he or she will come up with a treatment plan, specifically for the horse. The plan will be dependent upon how severe the condition is and the type of horse receiving care, for instance, whether or not the horse is a performance one. Common courses of care include of anti-inflammatory and analgesic medications such as acetaminophen and NSAIDs. Cortisone shots, which help reduce inflammation, may be used as might Visco-supplementation. The latter lubricates the cartilage. PRP therapy is a treatment that is being given an increased amount of consideration. It is used to help jumpstart the healing process.

PRP (Platelet Rich Plasma) therapy involves the use of a horse’s own blood platelets to promote healing. Blood platelets contain proteins called growth factors which are utilized by the body to heal itself. Whenever an injury occurs, the body sends growth factors to the injured area. PRP therapy is effective, in part, because a concentrated amount of growth factors are injected directly into the site of the injury. This helps the body repair itself faster than it would be able to do under normal circumstances. Typically, about six times the concentration of blood platelets are injected into the injured area.

PRP would be a good option for the treatment of hock degeneration joint disease because it can help the ankle joints repair themselves. When it is used in conjunction with anti-inflammatory and analgesic medications, it may help with the regeneration of the joint and surrounding tissues.

PRP therapy is typically done in a vet’s office but it can also be done on the farm or wherever the horses are located. To begin, the vet will first prepare the horse for the procedure. This will typically involve administering a nerve block and sedation. The horse will be standing when the vet draws about 52 mLs of blood in a syringe that is filled with 8 mLs of an anticoagulant solution.  The blood is then placed in a centrifuge, where it is spun until all of its components are separated. After this has occurred the platelets are drawn out and then re-injected into the hocks. Ultrasound guidance is not typically required. Options available to vets, in addition to autologous PRP therapy, include the use of PRP gel and sprays.

After a horse has received PRP therapy, they will be required to rest and the area will be bandaged. Multiple applications may be needed. The vet will determine whether or not additional applications are warranted. It may be, considering the fact that hock degenerative joint disease, is exactly that, degenerative. Ongoing treatment may be necessary to help stave off pain, discomfort and a lack of mobility. How often PRP therapy is needed will depend on the progression of the disease and what the horse is used for. Performance horses or those that are ridden often may, need more applications and may require them more frequently.

PRP therapy has proven to be an effective way to treat hock degeneration joint disease. Though it obviously can’t cure it, it can be used to manage both the lameness and pain commonly associated with it. When paired with anti-inflammatory medications and physical therapy, it can be very helpful, making life more comfortable for horses that, unfortunately, suffer from the condition.